Lee Clark succeeded Chris Hughton in June 2012.
Lee Clark has been sacked by Birmingham City, and assistant manager Steve Watson has also departed St Andrew's.
First team coach Richard Beale and head of recruitment Malcolm Crosby have been put in charge of the Blues side on a caretaker basis.
The club's Hong Kong-based owners brought the axe down on Clark after Saturday's defeat at Fulham edged Blues closer to the Championship relegation zone.
And a third straight defeat at home extended a dreadful sequence at St Andrew's, where Blues have only won once - in August - in more than 12 months.
Clark and Watson were both on one-year rolling contracts.
Clark attended a pre-match media conference at Wast Hills first thing this morning.
There was no obvious inkling of what was then to come as he launched an impassioned defence of his management.
He said that he would not quit Blues and critics should deal in the 'reality' of the club's current plight.
But the board, led by executive director Panos Pavlakis, decided to act after taking stock of another home disappointment.
And once all relevant parties were in agreement 6,000 miles away, the news was delivered to Clark just after lunchtime.